About Formicivora intermedia Cabanis, 1847
The northern white-fringed antwren (Formicivora intermedia Cabanis, 1847) is 12 to 13 cm (4.7 to 5.1 in) long and weighs 8 to 14 grams (0.28 to 0.49 oz). Adult males of the nominate subspecies F. i. intermedia have a white supercilium that extends down the neck, along the side of the breast, and widens on the flanks. Their crown and upperparts are smoky brown. Their wings are black with a wide white bar and white dots on the coverts. Their tail is black with white feather tips. Their face, throat, and underparts are black. Adult females have upperparts matching the male's. Their face is grayish and their underparts are dirty white to buff; their breast has variable dusky streaks and mottling. With the exception of subspecies F. i. orenocensis, males of all other northern white-fringed antwren subspecies have the same plumage as the nominate. Females of most subspecies, and both sexes of F. i. orenocensis, differ from the nominate and each other as follows: F. i. alticincta females have cinnamon-tinged whitish throats and underparts. F. i. hondae females resemble alticincta females but have paler upperparts. F. i. fumosa females are darker overall than nominate females, with more heavily spotted underparts. F. i. tobagensis females have buff-tinged white throats and underparts, with blackish spots on the breast. F. i. orenocensis of both sexes have reddish yellow-brown upperparts; females have white underparts with heavy black streaks. Northern white-fringed antwren subspecies are distributed across northern South America and southern Central America as follows: F. i. alticincta occurs on the Pearl Islands off southern Panama. F. i. hondae is found in Colombia, from Atlántico Department south to Antioquia Department, and along the Magdalena Valley to Huila Department. F. i. fumosa occurs in eastern Norte de Santander Department in northeastern Colombia, and in the western Venezuelan states of Zulia, Trujillo, Mérida, and Táchira. F. i. intermedia is found in the northern Colombian departments of Magdalena, Cesar, and La Guajira; in northern Venezuela from Zulia east to Monagas and Sucre, and on Margarita Island; and on Chacachacare island of Trinidad and Tobago. F. i. tobagensis is limited to Tobago. F. i. orenocensis is found in Venezuela south of the Orinoco River in Bolívar and extreme northern Amazonas, and occurs locally both north and south of the Orinoco in Anzoátegui, eastern Monagas, and Delta Amacuro. This bird species inhabits a variety of wooded landscapes, and favors the understorey to mid-storey at forest edges. Across most of its range, it occurs in deciduous forest, wooded savanna, gallery forest, mangroves, and thorn scrub. In southern Venezuela, the F. i. orenocensis subspecies is mostly found in campina woodland on white-sand soil or in young secondary forest. The species mostly occurs below 1,000 m (3,300 ft) in elevation, but reaches 1,200 m (3,900 ft) in Colombia and 1,600 m (5,200 ft) in Venezuela. The F. i. alticincta subspecies only reaches 200 m (660 ft) on the Pearl Islands.
